Contribution of smoking and air pollution exposure in urban areas to social differences in respiratory health

BMC Public Health

Table 4 Association between SES (educational level) and respiratory health indicators and its alteration by respiratory health risk factors Stepwise logistic regression analysis

		Frequent cough¹ N = 944	Frequent cough with phlegm production¹ N = 938	Bronchial asthma N = 1203	COPD FEV₁/FVC <0.7 N = 1172	FEV₁ <80% N = 1216	FVC <80% N = 1216
Model I SES (educational level) unadjusted, 3 categories as continuous variables	OR	2.01	2.02	2.33	2.46	1.83	1.99
	95%CI	(1.31–3.10)	(1.15–3.56)	(0.96–5.65)	(1.04–5.78)	(1.22–2.74)	(1.38–2.88)
	p-value	0.001	0.015	0.061	0.040	0.003	<0.001
Model II SES adjusted for occupational exposure ²	OR	1.95	1.97	2.28	2.40	1.78	1.95
	95%CI	(1.26–3.00)	(1.11–3.48)	(0.94–5.56)	(1.01–5.68)	(1.18–2.68)	(1.35–2.83)
	p-value	0.003	0.020	0.068	0.046	0.005	<0.001
	%-change	6%	5%	4%	4%	6%	4%
Model III SES additionally adjusted for current smoking	OR	1.91	1.95	2.18	2.26	1.71	1.92
	95%CI	(1.23–2.97)	(1.10–3.46)	(0.89–5.32)	(0.94–5.41)	(1.13–2.58)	(1.32–2.79)
	p-value	0.004	0.023	0.088	0.068	0.011	0.001
	%-change	10%	7%	11%	14%	14%	7%
Model IV SES additionally adjusted for 5-year mean PM ₁₀	OR	1.92	1.92	2.27	2.20	1.59	1.79
	95%CI	(1.23–2.99)	(1.07–3.41)	(0.92–5.59)	(0.91–5.32)	(1.05–2.42)	(1.23–2.61)
	P-value	0.004	0.028	0.074	0.080	0.029	0.002
	%-change	9%	10%	5%	18%	29%	20%
Model V SES additionally adjusted for distance to major road with >10.000 cars/day = 100 m	OR	not applicable	not applicable	2.28	2.12	1.56	1.78
	95%CI			(0.92–5.62)	(0.88–5.10)	(1.03–2.37)	(1.22–2.60)
	P-value			0.074	0.095	0.037	0.003
	%-change			4%	23%	33%	21%

¹ Only women living in a distance more than 100 m to the nearest major road with heavy traffic
² Dust, gases, vapours, wet conditions or extreme temperature
Abbreviations:
OR: Odds ratio for <10 years education versus >10 years education; 95%CI: 95% Confidence interval; PM₁₀: Particulate matter with aerodynamic diameter of ≤ 10 μm, calculated as PM₁₀ = 0.71*TSP; TSP: Total suspended particles; FEV₁: Forced expiratory volume in 1 second; FVC: Forced vital capacity; COPD: Chronic obstructive pulmonary disease; %-change: Calculated as the percentage reduction in the 'excess odds' due to adjustment for that factor

ISSN: 1471-2458